NOTES ON TAXONOMY AND BIOLOGY: This cyst forming nematode has
sedentary endoparasitic habits. Cysts are persistent tanned sacs derived
by the female body and contain the eggs. Cysts persist in soil for many
years. Second-stage juveniles (J2) emerge from the cysts, penetrate host
roots, and establish a specialized feeding site (syncytium) in the stele.
They develop into swollen females, which retain the eggs and produce large
egg masses. Females rupture root cortex and protrude from root surface.
At the end of the reproductive phase, females die and become rounded dark
or black cysts. These cysts are ambifenestrate and are provided of a long
vulval slit, small ovoid semifenestra, many bullae and a weak underbridge,
which is missed in some specimens. Heterodera oryzycola is morphologically
close to H.elachista,
H. oryzae and H. sacchari. The
separation of these species requires morphological and biochemical techniques
(Luc, 1986; Nobbs, et al., 1986).

GEOGRAPHIC DISTRIBUTION: This cyst nematode has been reported
only in India (CAB International, 2001).